FIGURE 2. Evolution of variation in risk-taking behaviour.

The outcome of evolution after 3  10⁵ generations of selection where individuals following the life cycle depicted in Fig. 1 play a single risky game between year 1 and year 2. a, In the case of an anti-predator game superficial explorers evolve high levels of boldness, whereas thorough explorers show low levels of boldness. b, In the case of a hawk–dove game superficial explorers are aggressive, whereas thorough explorers are non-aggressive. The bars correspond to mean trait values averaged over ten replicate simulations (error bars indicate standard errors).